Not all systems have sha256sum (Mac OS, for instance). Use the more common `shasum -a 256`.
$(DL_DIR)/$($(1)_TAR):
mkdir -p $(DL_DIR)
wget -N -P $(DL_DIR) $($(1)_URL)
- printf "%s %s\n" $($(1)_SUM) $$@ | sha256sum -c
+ printf "%s %s\n" $($(1)_SUM) $$@ | shasum -a 256 -c
$(DL_DIR)/$($(1)_DIR)/.prepared: $(DL_DIR)/$($(1)_TAR)
tar -C $(DL_DIR) -x$(if $(findstring bz2,$($(1)_TAR)),j,z)f $(DL_DIR)/$($(1)_TAR)